1. Electrical And Electronics Instruments
3rd Sem
Department of Electrical Engineering
Atmiya Institute of Tech. & Science, Rajkot

2. ELECTRICAL AND ELECTRONICS INSTRUMENTS
Principle and types of analog voltmeters
Principle and types of digital voltmeters
Principle and types of Multimeter
Single and three phase wattmeter
Single and three phase energy meters.
Magnetic measurements
Determination of B-H curve
Measurements of iron loss
Instrument transformers
Instruments for measurement of frequency and phase 2

3. Analog Instruments
An analog device is one in which the output or display is a continuous function of time and bears a constant relation to its input.

4. Classification
Classified based upon the quantity they measure (ammeter, voltmeter)
Classified according to the current that can be measured by them.(DC,AC)
Classified according to the effects used for working.
Classified as Indicating, Recording, Integrating.
Classified on the basis of method used for comparing the unknown quantity. (Direct / Comparison measurement )

5. Principle of operation
Magnetic Effect.
Thermal Effect.
Electrostatic Effect
Induction Effect.
Hall Effect.

6. Magnetic Effect

8. Force Between Current carrying Magnet

9. Force Between Two Current Carrying Coils

10. Hall Effects

11. Operating Forces
Deflecting Force.
Controlling Force.
Damping Force.

12. Supporting the moving element
Suspension
Taut Suspension
Pivot and jewel bearings.

13. Control Systems
Gravity Control.
Spring Control.

14. Analog Ammeters
Ammeters are connected in series in the circuit whose current is to be measured. The power loss in an ammeter is I2Ra.Therefore ammeters should have a low electrical resistance so that they cause a small voltage drop and consequently absorb small power.

15. Analog Voltmeters
Voltmeters are connected in parallel in the circuit whose voltage is to be measured. The power loss in an ammeter is V2/RV.Therefore voltmeters should have a high electrical resistance so that they cause a small voltage drop and consequently absorb small power.

16. Types of Instruments Permanent magnet moving coil (PMMC). Moving Iron
Electro-dynamometer type.
Hot wire type.
Thermocouple type.
Induction type.
Electrostatic type.
Rectifier type.

17. PMMC

18. Moving Iron Instruments Attraction Type

19. Repulsion Type Moving Iron Instruments

20. Electrodynamometer Type

21. Wattmeter

22. Power Measurement in 3 phase 3 wire system

23. Two wattmeter method

26. Energy meters

27. Single Phase Energy Meter

28. Poly Phase Energy Meter

29. THANK YOU